This invention relates to a wire processing machine for removing insulation from a wire. Machines of this type are designed to cut partially or fully through the thickness of the insulation layer or jacket of an electrical wire and remove the resulting end portion (called a slug) of the insulation, exposing a bare conductor at the wire's end.
It is known in prior wire processing equipment to remove an insulation slug by closing cutting blades on the wire, rotating the blades around the circumference of the wire and then pulling the slug off. Gudmestad, U.S. Pat. No. 3,951,016 is an example of a rotary wire stripper. Other devices use V-notch shaped cutting blades which do not rotate but instead make a partial cut on four sides of the circumference, with uncut portions being broken away upon slug removal. Kodera, U.S. Pat. No. 4,802,512 is an example. Kodera also provides for rotation of the wire during slug removal to twist the exposed end of the wire.
Sindelar, U.S. Pat. No. 4,261,230 has a pair of opposed flat or straight-edged blades. A full encircling cut of the insulation is effected by opposing movement of the blades transverse to the wire axis to roll the wire between the blades. Subsequent simultaneous transverse and axial movement of the blades twists the end of the wire.
The present invention arose from the need to strip coaxial cable. Coaxial cable has an outer insulation jacket, a shield layer, an inner dielectric or insulation layer and a conductive core. The outer jacket, shield layer and dielectric layer all have to be removed to prepare the cable for use. These layers are typically thick or made of hard to strip material, or both. In any case, acceptable stripping of coaxial cable requires a full encircling cut of the layers, making the use of stationary flat or V-notch shaped blades unsuitable. Accordingly, coax stripping is currently done by machines which have rotating blades.